(a) Field of the Invention
The present invention relates to a shroud for wearing with proximity fire fighting protective garments. More specifically, this invention relates to an aluminized shroud to be worn with proximity firefighting protective garments and helmet. More particularly, the invention is concerned with the provision of an opening in the shroud so as to accommodate a variety of face pieces of different SCBA (self-contained breathing apparatus) while meeting the dimensional requirements of the 2000 edition of NFPA 1976 (National Fire Protection Association). As well, the invention is concerned with the provision of a front closure system enabling the shroud to be easily donned and doffed, such that the wearer does not have to align the right and left sides in order to close it and have a continuous seal of the right half with the left, and that there is no chance of the right and left sides inadvertently separating.
(b) Description of Prior Art
National Fire Protection Association (NFPA) standard 1976 dictated the design and performance requirements for helmets, trousers and coats intended for proximity fire fighting. However, until the publication of the 2000 edition of NFPA 1976, there was no standard governing the design and performance of shrouds used for proximity fire fighting.
Until the publication of the 2000 edition of NFPA 1976 there currently existed two types of shroud used with proximity protective clothing. One was an aluminized hood with built-in radiant-heat reflecting visor that covers the entire head, shoulders, upper back and upper chest. This design of shroud is claustrophobic and restricts peripheral vision clearance. This design has fallen into disfavor.
The second type of shroud is a single layer of aluminized fabric (now multiple layers of material of which one is aluminized fabric) attached to the helmet suspension system. This shroud drapes over the shoulders and the upper chest and back of a firefighter. All of the various manufactured shrouds of this second type have left and right sides that overlap and close at the front by means of hook and pile fastener tape. The completeness of the seal of two sides depends on the attention the wearer pays when aligning the two sides and the corresponding hook and pile fasteners. Occasionally the two sides would not be properly aligned and closed. As a result, there could be gaps in the protection offered by the shroud or the two sides could separate during the rigors of proximity fire fighting.
Furthermore, since there was no standard governing the dimensions of the face opening, the manufacturer was at liberty to design the face opening of the shroud with the dimensions it chose. It was not uncommon to have a gap in protection between the SCBA face piece and the edge of the face opening in the shroud.
With the publication of the 2000 edition of NFPA 1976, it is now necessary for the shroud to meet stringent design and performance requirements. In particular, NFPA dictates that the face opening shall measure 55/8 inches (+0/-1 inch) in any direction or, if designed to be worn with a specific SCBA face piece, shall overlap the outer edge of the specific SCBA face piece-to-face seal perimeter by not less than 1/2 inch.
As a consequence, it is more difficult to ensure that the shroud face opening interfaces with the SCBA face piece. Since there are at least seven different brands of SCBA commonly used in proximity fire fighting--each with its own design of face piece--it has almost become necessary to have one design of shroud for each brand of SCBA face piece.
Furthermore, NFPA 1976 requires the shroud itself to have a thermal protective performance rating of at least 35. In order to achieve this level of thermal performance, it is necessary for the shroud to be constructed of either a single layer of thermal reflective and insulating material or of multiple layers of thermal insulating and reflective material. The thicker single layer or multiple layers produce a shroud that is stiffer than the earlier versions.
Another consequence of the stiffer shrouds is that it has become more difficult to both align and securely close the two halves of the shroud with hook and pile fastener. As well, it is more likely that the front opening of the shroud accidentally gapes during the rigors of proximity fire fighting.
Another disadvantage of this second type of shroud is that it is normally attached to the helmet with the consequence that radiant heat easily penetrates through the gap between the shroud and the helmet outer cover and may produce real discomfort to the firefighter.